Immunology 5

Question 1

what’s the structure of TCRs

Answer 1

2x polypeptide chains (a + B)
S-S bonds

Question 2

what’s the structure of MHC I

Answer 2

only a-chain contributes
B2 microglobulin to aid binding

Question 3

how are TCR formed

Answer 3

V(D)J recombination
a - V & J
B - V & D & J
RAG used

Question 4

what’s the structure of MHC II

Answer 4

B + a chains
Bothe contribute equally

Question 5

what type of T-cells do MHC I bind to

Answer 5

the TCR of CD8

Question 6

what type of T-cells do MHC II bind to

Answer 6

the TCR of CD4

Question 7

what’s the differences between MHC I and II

Answer 7

MHC I
- binds to intracellular proteins
- present on most mast cells
MHC II
- binds to extracellular proteins
- on APCs

Question 8

REMEMBER TO LOOK AT MECHANISMS FOR CLASS I AND CLASS II ANTIGEN PRODUCTION

Question 9

what cell primes naive T-cells

Answer 9

DCs

Question 10

what’re the steps of priming naive T-cells

Answer 10

1. presentation by APC
2. DC picks up antigen -> lymph node
3. T cells recirculate blood vessels -> lymph node
4. if T cell encounters DC which has the antigen
   - T cells differentiate -> effector T-cells
   - if not = t-cell leaves via lymphatics

Question 11

what’s the function of b-cells

Answer 11

present to effector t-cells

Question 12

what is it that cytotoxic t-cells do to cause damage

Answer 12

perforin forms pores in membranes
cytotoxic granules

Question 13

what’re the 3 types of helper t-cells
+what do they each do

Answer 13

Th1- release IFN-y + increase macrophages
Th2- parasitic
Th3- helps production

Question 14

what’s the benefit of self-tolorance

Answer 14

prevent t-cell activating w. self-antigens

Question 15

what’s the name of immature t-cells

Answer 15

thymocytes

Question 16

what’re the steps of developing self tolerance

Answer 16

1. thymocytes -> thymus
2. TCR gene segments rearrange
3. express CD4, CD8, TLR all at the same time
4. +ve selection (cells recognised MHC I/II) -ve selection (binds to self peptides = apoptosis)